import React from 'react';
import ReactDOM from 'react-dom';
class Hello extends React.Component { 
	constructor() { 
		super() 
		this.txtRef = React.createRef() 
	}

  change = () =>{
    console.log(this.txtRef)
  }

  render() { 
    return (<input type="text" onBlur={this.change}  ref={this.txtRef}/>)
  } 
} 
ReactDOM.render(
<div>
  <Hello />
</div>, document.getElementById('root')) 